Today, many people live and work in an environment that may contain dangerous levels of radioactivity. The main feature of such radiation is that it is difficult to detect using small-detection devices and there is a possibility of a living organism to accumulate radiation dose. Also, exceeding an acceptable accumulated dosage can lead to fatal consequences—radiation sickness and hereditary disorders.
Therefore, attempts were made to provide human beings with personal device which is always at hand and can indicate not only the existing intensity of penetrating radiation to which the wearer is exposed, but also the dosage of accumulated radiation thereof. One of the first engineering solutions relating to development of such small-size devices was a compact wristwatch and radiation monitor assembly. The assembly consists of an electronic timepiece within digital or analog display, and a component that operates radiation monitor and contains semiconductor detector and controller. A Radiometer is built on the basis of a microprocessor to combine radiation monitoring with timekeeping.
Unfortunately, the device described above does not allow long-term precise monitoring of radiation. First, the semiconductor detector is not precise enough: it is responsive to other types of validation, for example high-frequency omissions from mobile phones and other kinds of effects, including mechanical effects. On the other hand, semiconductor radiation detectors consume a lot energy, and the user has to change power supply units quite often. This is why the producer uses two independent power supplies for each component of the assembly.
The Yperwatch [2] wristwatch (Switzerland) is known. A patent was taken out for this watch in Switzerland, Japan and other countries. The assembly consists of two components: an electronic timekeeper with an analog display, where the hands indicate the information and radiation monitor, and which contains semiconductor detector and controller. This watch features at least two printed-circuit boards connected with each other by a flexible conductor; the mechanism responsible for turning the analog hands of the watch is placed in hollow space on one of the printed-circuit boards.
The Yperwatch is more fail-safe and feasible, but does not solve the main problem. A semiconductor radiation detector is responsible to other, nonradioactive emissions, mechanical and climatic effects. It also requires a high-voltage current. It is not possible to eliminate this problem of semiconductor detectors in certain kinds of equipment.
The monitoring of radiation can be done by means of Geiger-Muller counter, which is used in individual dosimeters. However, such devices have not been used in wristwatch and other compact devices until today, because the Geiger-Muller counter requires constant voltage of about 400V.
The aim of the current invention is to use a Geiger-Muller counter as a radiation detector in a personal wristwatch and to ensure its functioning over a long period of time. A voltage changer, able to change voltage from 1.5V-3V to 400V, is needed to make the Geiger-Muller counter function in a wristwatch and other compact devices.
There is known a voltage changer containing an energy source, for example: solar cell or solar battery, converter of direct current into alternating current by means of a switch key, an electric transformer and AC/DC converter. The switch key disconnects one winding or another, and windings are made different so as to make it possible to adjust the output voltage [3].
The disadvantage of the known device and its implementation method lies in impossibility to adjust precisely the output voltage and relatively high energy consumption.
A device for converting direct current into a high-voltage direct current was taken as a prototype for voltage changing method and voltage changer itself. The device has several outputs a pulse converter with a controller, which operates electronic switches, a step-up transformer with an AC/DC converter, and a filter, where the output voltage is forwarded to controller through divider [4].
Disadvantage of the known device and its implementation method is that feedback leakage wastes a lot of energy, and for this reason the device fed by compact power supply unit cannot keep functioning over a long period of time.
The object of current invention is to use Geiger-Muller counter as a radiation detector in a personal wristwatch and to ensure its functioning over a long period of time.